Dialkyl sulfosuccinate composition



Patented May 11, 1948 UNITED STATES PATENT OFFICE DIALKYL SULFOSUCCINATE COMPOSITION No Drawing. Application May 27, 1946, Serial No. 672,692

3 Claims.

This invention relates to surface-active compositions, and more particularly to compositions containing surface-active dialkyl sulfosuccinates in which the alkyl groups contain from 5-10 car-- bon atoms prepared in the form of dry, watersoluble powders by admixture with a hardening agent.

The diesters of suliosuccinic acid with alcohols of 5-10 carbon atoms are well-known wetting and emulsifying agents, their preparation being described in U. S. Patent No. 2,028,091. Of these compounds the di-(2-ethyl-hexy1) sulfosuccinate, in the form of its sodium or other alkali metal salt, possesses the highest wetting power as measured by the standard Draves test. The diamyl sodium sulfosuccinate and the dihexyl sodium sulfosuccinate are somewhat more easily soluble in water than is the dioctyl compound, and all three are sold commercially in large quantities. The dinonyl and didecyl sodium sulfosuccinates are at present used principally as emulsifying agents and detergents, although they are also good wetting agents.

Heretoiore these wetting agents have been sold commercially either as solutions in water or aqueous organic solvents or in admixture with inert organic or inorganic diluents or in pure 100% form. The solutions are used where the surfaceactive agent is desired in a quickly water-soluble form, but require special containers of glass, stainless steel or aluminum as well as the shipment and storage of substantial quantities of solvent. The dry powders usually contain about -20% of the dialkyl sulfosuccinate in admixture with 80-90% of an inert diluent such as cerelose or sodium sulfate. These dry mixtures are watersoluble and free-flowing, but also necessitate the shipment and storage of large quantities of diluent material.

In their pure or 100% form the dialkyl sulfosuccinates of aliphatic alcohols of 23-10 carbon atoms are solid waxeswhich dissolve very slowly in water. For example, pure sodium dioctyl sulfosuccinate must be allowed to stand in water at room temperature for 24 hours to prepare a 10% solution. As is noted above, the diamyl and dihexyl esters dissolve in water more rapidly than the dioctyl ester, but are considerably more hygroscopic.

Heretofore the only known method of overcoming the inherent stickiness and slow water-dispersibllity of the dialkyl sulfosuccinates was to mix them with relatively large quantities of organic or inorganic diluents such as sugars or sodium sulfate. However, as noted above, this method required the use of considerably more diluent than wetting agent. The presentinvention is based on the discovery of a hardening agent which will overcome the inherent stickiness of the dialkyl suliosuccinates even when used in relatively small quantities.

I have found that the alkali metal salts of benzoic acid, such as sodium, potassium or ammonium benzoates, will transform the normally sticky dialkyl sulfosuccinates of alcohols of 5-10 carbon atoms into hard, brittle materials that are readily powdered after drying. The alkali metal benzoates are effective for this purpose even when used in relatively small amounts; thus, for example, the addition of 5-10 parts by weight of sodium benzoate to -95 parts of sodium dioctyl sulfosuccinate will change the sulfosuccinate from its normal waxy consistency into a nonsticky solid that can be dissolved in water in less than 5 minutes. When the same proportion of sodium benzoate is added to a concentrated aqueous solution of sodium dioctyl sulfosuccinate the resulting mixture can be spray-dried. This is an extremely important discovery, for previous spraydried compositions of the dialkyl sulfosuccinate wetting agents have always contained more than 50% and usually about 90-95% of inert diluent.

The compositions of my invention therefore contain, as essential ingredients, a dialkyl ester of sulfosuccinic acid in which the alkyl radicals contain 5-10 carbon atoms together with an alkali metal salt of benzoic acid. The compositions may also contain other ingredients if desired such, for example, as sodium phosphate, soap, other detergents, inorganic fillers and the like. The alkali metal benzoate should be present in amounts of at least 5%, based on the weight of the dialkyl sulfosuccinate; but larger quantities may be and usually are employed. In general, the amount of alkali metal benzoate will vary from about 5% to about 50%, based on the weight of the dialkyl sulfosuccinate, although amounts up to may be employed if desired. Quantities of 15-60% are frequently advantageous, for the increased amounts of alkali metal benzoate causes even more rapid solution of the dialkyl sulfosuccinate in water, and produces a quickly dispersible composition.

The compositions of my invention are preferably prepared by mixing the dialkyl sulfosuccinate with the alkali metal benzoate in the presence of an aqueous solvent which may be water or a mixture of water and ethanol, propanol, butanol, etc., followed by evaporating the solution to dryness. Drying may be effected in a tray drier well-suited for use in wetting out textiles, for the preparation of photographic film-developing powders, and for a wide variety of other uses requiring a water-soluble surface-active agent of high wetting power.

What I claim is:

1.,A water-soluble composition .consisting essentiallyot h drymixtureo! 50% $095% byzweight of a dialkyl sulfosuccinate in which the alkyl -10 groups contain from to carbon atoms and aqueous solution containing the sodimn and dialkyl sulfosuccinate, andare obtained 'asingredients of the tray-dried, drum-dried or spray-dried products. However, itis an advers tage of my invention that inert materials need not be used unless they are desired fort-special purposes since dry, free fiowing powders which are readily, and rapidly soluble in vwater are ob- 50% to 5% by weight of an alkali metal benzoate.

2; Aiwater' sohibi composition consisting essentially ot a dry mixture of 50% to 95% by weight of a dioctyl' sulfosuccinate and 50% to 5% by ;.weig'h't of an alkali metal benzoate.

3. A water-soluble composition consisting essentially of ad-ry mixture of 50% to 95% by weight of a dialkyl sulfosuccinate in which the alkyl groups contain from 5 to 10 carbon atoms and to 5% by weight of sodium benzoate.

tamed simpliby mixing the allihli metal benzoate I with the dialkyl suliosuccinate".

m oneitypical example, 7 5 parts by, weight of sodium benzoate and 235 parts of an aqueous solution'oi sodium dioc'tyl smtosuceinate werefdiS- solved in 71.5rparts of water. 'Iheresultingfsolution was spraydried in the above described sptay-dryingJeqUipmentL The resulting d y nOn caklr'igpowder was rezmiilywater-s01uble', and was EMIL A. VITALIS; v

REFERENOES'CITED a The w following references are of recordw-imthe; on file of thispatent:

UNITED STATES PATENTS Number Name Date 2,149,240 Crossley Fb'r28 1939 Caryl et a1 Nov. 21; 1939" 

